While it is hoped that molecular detection and intervention will one day provide a more effective treatment modality, currently, mammography has proven to be the most effective means of reducing breast cancer morbidity and mortality. Screening mammography is an extremely challenging application of x-ray imaging, where dose, contrast, resolution and cost are all critically important. Glass capillary x-ray optics have properties that make them ideally suited to address these problems. Two basic configurations of capillary optics will be investigated. The first employs an innovative x-ray optics technology in a pre-patient configuration to produce a tunable, monochromatic, highly parallel x-ray beam from a conventional radiographic x-ray source and demonstrates its applicability for high contrast clinical mammography. Polycapillary Kumakhov optics will be employed to efficiently collimate the beam from a conventional x-ray tube source. The collimated beam will then be diffracted from a wide area monochromator crystal. This will allow routine screening mammography to take advantage of the enhanced contrast produced by monochromatic radiation as well as innovative imaging techniques such as refractive index imaging, dual energy imaging and k-edge tuning. The second configuration employs post-patient capillary optics in a magnification mode. Capillary optics produce tremendous improvements in image quality by virtually eliminating scattered radiation and providing greatly enhanced system resolution and MTF at all lower spatial frequencies when placed between patient and detector. The challenge is to develop a strategy to produce significantly larger capillary optic systems. An array of relatively small (1 cm) individual capillary optics will be assembled in a rigid grid structure which would be scanned across the breast in a single pass to produce a high resolution, digital image.